Multiple format string vulnerabilities in isns.c in (1) Linux SCSI target framework (aka tgt or scsi-target-utils) 1.0.3, 0.9.5, and earlier and (2) iSCSI Enterprise Target (aka iscsitarget) 0.4.16 allow remote attackers to cause a denial of service (tgtd daemon crash) or possibly have unspecified other impact via vectors that involve the isnsattrquery and qryrsphandle functions, and are related to (a) client appearance and (b) client disappearance messages.